Feeding mechanism for tools



June 6, 1950 P. s. CLAUS EI'AL FEEDING MECHANISM FOR TOOLS 2 Sheets-Sheet 1 Filed April 28, 1947 INVENTOR. PHILIP S. CLAUS BY EBER J. READMAN June 6, 1950 P. s. CLAUS ETAL FEEDING MECHANISM FOR TOOLS Filed April 28, 1947 2 Shets-Sheet 2 INVENTOR. PHILJP S. CLAUS BY EBER J. READMAN Patented June 6, 1950 5r 2,510,330 V FEEDING MECHANISM Fort Too s Mich trustee hint si an; and Eber J. mien, Plymouth, Mich assignors', by direct'and ine'sne assignmerits, to Willi'am'A. King;

Highland Park,

-i Application 'April 28, 1947, Serial No. 744,440

' 14 Clainis This invention relates to tool feeding 'mecha nisms and particularly tofanfautomatic feeding mechanism for cutting', milling, reaming 7 and drillingoperations. f f j An important obj ect, of this invention is to pro-. vide an' improved tool feeding mechanism which is ruggedly and compactly constructed and assembled, and which associates, the operating elem'ents in a novel manner for advancing, controlling and retracting the to'ol automatically and in desired conformity'to the'character of'the mate rial being worked on. Another important'object of the invention" is to provide an improved assembly of Operating parts forsuch a mechanism which are positive in their interrelated actions with one another and which "perform their desired "functions automatically in def nite sequences and in a highly efficient manner, A further, important object of the invention is to provide such a mechanism comprising parts which are capable or beingfmannfactured at low cost and easily and' quickly assembled and which are capable of continued operation over long periods of time without impairment,

More specifical1y,it is important object of this invention to provide infsuch a tool feedingmechanism a, novel, drive connection between, the source of power and the tool rotating spindle and the inertia members employed for advancing the spindle toward "the Work, :which drive connection is selfeoperable to varythe force with which the tool progresses throughthe work depending uponthe varyingresistance encountered by the tool in the ;work and to-prevent the tool from too rapid advance through the'v'vork. -An'important 3 feature of this drive connectionis'jthe provision of a coupling sleeve'for' transmitting the rotary impulses from the drive member to the spindle and also conveying the impulses to the inertia members to rotate the same; The coupling sleeve telescopingly overlaps upon the drive member; and the spindle and all three elements are shaped with novel means which couples the semen): gether'ior joint rotation yet provides a self controlled axial movement of the spindle, The 4 novel means comprises interengaging helical splines which are so related to the direction of rotation of the drive and driven members thatlthe axial thrust ofthe spindle is varied dependi n'g upon the resistance or other interference encountered by the tool in the Work throughwhich. it is progressing. j.,

Another important object of the invention is the provision of novelbrake means and associated elements which quickly retards the rotation; of

the inertia members when the parts of the mech-Z anism have returned to their initial starting position'.flAssociated with the brake-means are self operable control elements forming part of the inertia driving means which instantly disengage-the brake means as-soon asrotary drive impulses are transmittedt the spindle at the commencement of each successive stroke thereof,

thereby immediately releasing the load" "which would' iothe'rwise bimposed upon the-power Source," When retarding the rotationof the in-- ertiamembers, the brake meansiunctions quickly yet in'such a manneras to prevent the suddenim osition of a heavy load on'the power Source and driving connections therefrom. a

' Another imp rtant feature of the invention'is theprovision'ora novel automatically releasable axial'feeding connection between the spindle and the inertia membersior advancing the spindle axially in one, direction which is automatically e'fiectiv'e at a" predetermined position in "the ad;-

vanceof thespindlew to release the feeding con nection and thereby discontinuing the' advance or 'the spindle.) This ieeding connection, takes the novel form of amember or collet carried by,

spindle and encirclingflthie same, having, in-' herently resiliently xpandible portions which are engageable with a linearlyuniovable sleeve associatedwithlthe inertia members andre'spone sive to :the centrifugalforce developed thereby. To improve theieeding movement of the spindle, the expandible portions or the collet are concentrically-melatedto the axis of-the Spindle and. are shaped in a novel manner for continuous abutting engagement With the feed sleeve associated with the inertia members regardless of whether the collet is connected to the sleeve for,

advancing the spindle or not.

Various other objects,advantages and meritorious-features will become more fully apparent from the following specification, appended claims and accompanying drawings wherein:

tion showing position, 7 i

Fig.2 is a longitudinal sectional view of the mechanism similar to Fig.1 but showing the parts"; intheiontermost positiono'fthe tool,

Fig. 3 is a detail view illustrating the brake devices for retarding therotation of the inertia mb rs nd showi n db rdl i li e] a epo it qn ofthe mei iqqneri ing the de-;

Fig. 4 is a fragmentary view in elevation of the associated parts of the brake mechanism, and

Fig. 5 is a cross-sectional view taken along line 5-5 of Fig. 2.

The embodiment of the invention illustrated in the drawings comprises a driven shaft or spindle I0 which is provided with suitable means such as the socket l2 at the outer or right end as viewed in Figs. 1 and 2 for detachably receiving a tool. member extending substantially the length of the mechanism as shown or divided into two or more; aligned shafts coupled together for joint rotation. both rotation and axial movement; and is rotated from a source of power, such as the electric motor generally indicated at I 4, the housing of which may be secured to the housing enclosing the mechanism as shown.

The armature of the electric motor carries a projecting driving shaft IB, having detachabl-y secured thereto a driving member I8 which projects forwardly in alignment with the shaft 16 as an extension thereof and is provided with a collar l9 encircling the shaft l6 through which a pin shown in dotted outline may extend to removably secure the driving member I B to the armature shaft. The inner endof the driven shaft or spindle I0 is operatively coupled to the drive member 18- for rotation thereby. 7 Freferably this is accomplished by the provision of a coupling sleeve 20 whichtelescopingly overlaps upon the d-rive memberl8 and the rear end of the spindle and is splined thereto. A novel feature of the invention is the use of helical splines in place of axial splines which as will be later pointed out control the advance of the spindle and tool when certain elements interfere with the operation of the tool. The helical splines of the spindle Ill and the drive member l8 are respectively indicated at 22 and 24. The coupling sleeve 20 is internally helically splined for engagement with the s lines of the two members which it encloses. The drive member [8 and the inner end of the spindle H! are maintained out of abuttingengage'rhent'with one another by a pin 26 which extends transversely across the sleeve 2fl'be'tween these two members.

' The operating parts of the mechanism are preferably housed in anelongated tubular structure gradually reducing in diameter toward the working "end thereof. Asshown, this housing comprises an elongated relatively large diameter tubular section 28 to which the reduced forward end 30 of the motor housing attached. The housing section 28 extends for the major portion of the length of the "mechanism and is'preferably jogged intermediate its ends to provide a forward extremity of reduced diameter. Detachably slidably received within and secur-edto the forwardendof thehousingsection 28 is a second shortersection 3.2. This last section contains anaxial adjustable mounting member 34 encircling the. forward end of the spindle in spaced relation thereto and projecting slightly beyond the end of the tubular section 32 where it may be engaged for adjustment.

The forward end of the spindle II] is rotatably journaled a bearing 36 which is carried in the adjustable mounting 34. The remote inner end of the spindle is supported by the coupling sleeve 20 which in turn is rotatably supported by two corresponding I spaced apart bearings 38-38. The latter are fitted within and enclosed The spindle [0 may be an elongated 1 I4 isdirectly The shaft or spindle ill mounted for I l and 2.

limiting further separation of the bearing assem- 4 the two bearing assemblies 38-38 are slidably mounted on the outer peripheral surface of the sleeve 20. The outer races of these bearing assemblies slidably engage the inner peripheral face of the annular member 40. The two bearings are yieldingly resistantly maintained apart by a coiled spring 42 which is under tension and normally keeps the two assemblies in their maximum spaced apart relation as shown in Figs. Any suitable means is provided for spindle i0 and thereby carry the tool toward and; through the'object upon which the work is performed, there is provided inertia means in. the

form of a plurality of weighted members or balls 48 which are arranged in circularly spaced relation around an intermediate portion of the spindle. These balls are carried in a rotatable ball retaining structure or cage comprising a' rear annular .plate or disc 50, a front annular plate or disc 52, and radial fins 54 extending be tween the two plates and connecting the same together to form a plurality of outwardly open-' ing ball retaining pockets. Preferably the ball cage structure is formed out of one member and as a result the annular plates and fins are integrally joined together. The balls are each mounted in a pocket and have a permitted radial travel as a comparison of the two positions of the balls in Figures 1 and 2 will show.

In order to convert the centrifugal force of rotation of the weighted members or balls 48 to a linear force for axially advancing the tool to and through a work piece, a conical shaped member 56,- termed a pressure or pusher plate, is arranged to overlie the open mouths of the ball retaining pockets as shown in Figure 1. pusherplate converges forwardly and the forward end thereof is secured to a collar 58 which is independently rotatably mounted by means of a ball bearing assembly 60 on the rear end of a feed sleeve 62 enclosing an intermediate portion of the spindle ID. The feed sleeve 62 is independently rotatable about the spindle In by the provision of a bearing therebetween of bronze or other suitable material for this purpose indicated at 64.

Improved disconnectible means is provided for operatively connecting the feed sleeve 62 to the spindle I!) for advancing the same, which means is effective at a predetermined point in the advancement of the spindle to break on the connection and restrict further advance of the spindle. This disconnectible 'means comprises a sleeve-like member or collet 66 of novel design which is carried by the spindle and encircles the same in concentric relation thereto. The forward end section of the collet 65 tightly embraces the spindle and is secured thereto by a transverse pin 68 extending through the spindle from oneside to the other. The rear end section of the collet is divided or split longitudinally into a plurality of segmental portions 10 which are inherently by an annular member 40. The inner races of sprung outwardly radially of the spindle in po- The sltlon to be engaged by the forward end of the feed sleeve.

Preferably the form of connection between the feed sleeve and the collet is such that at all times the collet is maintained in abutting engagement with the sleeve regardless of whether or not the axial drive connection between the feed sleeve and the spindle is in'operation. This is accom-' plished by so mounting the collet on the spindle with respect to the feed sleeve 62 thatat all times the extremities of the segmental portions mare under the forward end of the feed sleeve in all positions of the spindle. This condition is shown in the two views of Figures 1 and 2-; Each segmental portion it is provided with an'outwardly extending shoulder l2 which are located short of the rear end thereof. All the shoulderson the respective segmental portions are mounted in the same plane and circularly align with one another. Each shoulder is provided on the 'rear side thereof with a radial face extending substantially perpendicular to the axis of the-spindle and adapted to project into position to be en gaged by the forward end of the feed sleeve when the latter is advanced forwardly by the centrifugal action of the balls 18. Each shoulder 12 is also provided on the front side thereof with a tapering or converging face which as will be described more particularly hereinafter is adapted to be engaged by suitable means in a forward position of the spindle to compress or wedge the segmental portions downwardly and withdraw the rear face of the shoulder from abutting engagement with the forward end of the feed sleeve. The inherent spring-mess of the segmental portions causes them to spring out away from the peripheral surface of the spindle and into engagement with the feed sleeve. In the initial starting position shown in Fig. 1 the peripheral portions of the segments iii rearwardly of the shoulders l2 abut the inner peripheral'surface of the feed sleeve. When the feed sleeve advances forwardly from this position it abuts the shoulders l2 and carries the spindle forwardly therewith. The concentric relation of the segmental portions and their respective shoulders 12 to the feed sleeve insure an evenly distributed pressure on all sides of the collet advancing it and the spindle smoothly with a minimum amount of wear between the parts.

The forward bearing mounting 34 is provided with an inwardly projecting externally threaded tubular portion i l, the inner diameter of which is greater than the spindle it in order to provide clearance therebetween. A coiled spring i6 encircles the spindle in this clearance and is seated at one end on the inner race of the bearing assembly 36 and at the other end on the collet 66. Adjustably threaded on the tubular portion '14 is a sleeve 18 which projects inwardly beyond the inner end of the former and approximately the length of the housing section 32. The sleeve 18 is internally shouldered to provide a seat 80 for the outer race of a roller bearing assembly 82. The inner race of this ball bearing assembly has a diameter permitting the forward end section of the collet 66 to slide therethrough as shown in Fig. 2 but insufficient to permit the shoulders I2 thereof to enter without first being compressed thereby toward the peripheral surface of the spindle. Actually the inner race of the bearing assembly 82 functions as a control means for compressing the spr'ingyportions of the collet to withdraw the'shoulde'rs from engagement withthe forward end of the feed sleeve 6, 62. Fig. 2 illustrates the maximum forward position of the parts just at the point when theshoulders 12 have withdrawn inwardly sufficient-F iv to clear the forward end of the feed sleeve.

In the next instant the coiled spring I6, which has been compressed by the forward advance of the spindle, will act through the collet to thrust" the spindle and collet rearwardly to the initial starting position. This movement will occur before the feed sleeve is retracted and the collet will slide inwardly relative to the sleeve until it substantially abuts the forward end of the bush-.

ing. 64.. Threaded adjustment of the sleeve 18 witherespect to the mounting 34 will vary the. axial position of the bearing assembly 82 and; thereby vary the point in the advancement of.

the spindle when the connection between the. collet and the feed sleeve is broken off.

- Carried on the feed sleeve 62 is a radial abutment in the form of a collar $5. In the-forward position of the feed sleeve as sho.vn ;in;;Fig-.-, 2:

this-collar'is adapted to abut a ring-shaped stop member 86 which is slidably fitted into the inn er end of the adjustable sleeve 18 and is axially urged inwardly by springs 38.

tweenthe feed sleeve and the stop memberjiB.--. A large coiled spring Sit is provided i the ciated parts to initial starting position. One

end of this spring, is seated on the inner end of,

the housing section. 32 and the other end sis seated on the outer rim of a slightly conical sleeve 92. The reduced forward end of this sleeve is shaped to bear upon the outer race of a ball bearing assembly at having the inner race thereof held to the feed sleeve 62 for axial movement therewith. The bearing assembly 94 al;- lows the spring fill and its seating member 92 to move axially with the feed sleeve without rotating therewith.

An important novel feature of the invention resides in the means for rotating the retaining structure or cage and the inertia members therein directly from the source of power rather than indirectly from the spindle shaft it. This is accomplished by directly connecting the coupling sleeve 2% to the ball retaining structure, which coupling sleeve as previously described is di.- rectly connected to the driving member 24. As

shown in Figs. 1 and 2. the reardisc 50 of the ball retainer is provided with a rearwardlycx tending circular flange 96 having an inner, diameter of a size to slidably of the coupling sleeve. The two are rotatively coupled together by two different pins 98 and Hill on diametrically opposite sides of the spin One pin as is secured to the forward end of the coupling sleeve and projects radially outdle.

coupling sleeve, such distance being determinedby the amount the slot is oversize the pin 98 in the axial direction. The opposite pin l flll is secured to the circular hub 96 and projects. radially inward into an elongatedslot H34 formed in the outer periphery of the coupling sleeve en closed by the flange. The slot extends axiallyand like the opening lElZ' will permit the ball retaining" structure to move axially. 'The' two pins 98' and I00 fittingtheir respective openingsfunctiori to The springs 88 serve, to cushion the shock of engagement be fit over the forward 191;

key the forward end of the coupling sleeve to the. ball retaining structure for joint rotation but permit a Slight axial shiftable movement of the structure relative to the sleeve.

Another important feature of the invention is the provision of a brake device for retarding. r0.- tation of the ball retaining structure when the parts return to their initial starting position shown in Fig. 1 thereby quickly slowing the rotation of the inertia members in order to retractthe feed sleeve for a second operating advancement of the spindle. Novel means is associated with. the brake device for instantly releasing the same as soon as the coupling sleeve is rotated to advance the spindle thereby immediatel reducing any load on the motor I4 which would otherwise occur when the motor is energized. This novel means also functions to reduce the rotation of the inertia members in such a manner as to prevent any undue strain being imposed upon the motor.

Referring to Figs. 1 and 2, the brake device comprises an annular member I66 encircling the hub 96 of the ball retaining device and provided rearwardly thereof with an outwardly extending circular flange I118. The flange extends in overlapping relation to the forward end of the stationary annular body 48" previously described. The forward end of the bod 49 carries a. facing of friction material II O with which the flange: I08 may engage asshown in- Fig. 1. In. lieu of attachment to the front end of the member 40, the friction material may be secured to the flange. The forward end section of the annular member IIlIiof the brake device is widened interiorly to form a clearance entirely around the hub 98 in which a coiled torsio spring I I2 is located. One end of this coiled spring is attached to the member I06 as indicated at I I4. The other end of the spring is attached to the hub 96 as indicated. at 6-. The spring couples the annular member- I06 to the hub 96 of the ball retaining structure but permits a limited resisted relative rotation of one with respect to the other.

The annular member Hit of the brake device: is provided with an inwardly projecting rib II 8 which is interposed between the rear end of the hub 96 and the shoulder 36 of the coupling sleeve- Carried by the shoulder 45 are two corresponding" cylindrically shaped pins mar-42s located on the shoulder diametrically opposite to one another as shown in Figs. 1 and 2. These pins are mounted in the shoulder and the coupling sleeve- 20- of which the shoulder forms a part in such amanner that cylindrical portions thereof projectforwardly beyond the front edge of the shoulder as shown clearly in Fig. 3 for abutting engagement with the rib H8. Substantially opposite each pin I-20I20, the rib H8 is provided with. a notch I22 into which the pins are adapted to seat when the parts are in their initial starting position as shown by the full lines in Fig. 3. Each. notch I22 is provided with an axial extending sidewall serving as a stop for the pin and an in-- clined wall up which the pin may travel when; relative rotation occurs between the coupling sleeve 20 and the annular member m5.

As previously mentioned, the full line position of the parts in Fig. 3 represent the initial starting position when the parts are at rest. When the motor I4 is energized, the coupling sleeve is rotated in the direction tending to move the pins I20-I20 up the inclined faces of the notches. I22, such as in the direction of the arrow indicated'. in. Fig. 3. Since the sleeve and the pins fill-4.20 rotate ina fixed plane, and sincethe annular member and the hub 96 have a limited axial play, the initial rotating movement of the sleeve will cause the pins to travel up the inclined sides of their respective notches forcing the annular member to shift forwardly axially of the mechanism. This forward movement will shift. the flange I08 away from engagement with the frictional facing III] thereby releasing the brake. From that point on until de-energization of the motor, the brake is maintained in brake releasing position. As previously pointed out, the coiled sprin II2 permits a limited rotative movement of the annular member I06 relative to the sleeve to enable the pin to travel up the inclined side walls of the notches. The axial thrust applied by the pins I20I20 on the rib I I8 is transmitted by the latter to the hub 95 to axially shift the same and the ball cage slightly forward or to the right as shown in Figs. 2 and 3. The dotted lines in Fig. 3 show the position of the parts in brake released condition.

In order to positively limit the relative rotation of the brake member I06 to the hub 96 of the ball retaining structure, a rectangular recess I24 is formed along the leading edge of the brake member as shown in Fig. 3 into which a pin I26 fixed to the hub projects. The recess is oversize the pin, allowing the brake member Hit a limited rotational movement relative to the coupling :sleeve 20 and the ball retaining structure. When the pins I2B-I2U are seated fully in their respective notches I22, the pin I26 abuts one end of the recess. When the pins I26 ride out of the notches to the extent sufficient to release the brake the pin I26 will abut the opposite end of the recess as is evident by the position of the parts in dotted outline in Fig. 3. As a result of the connections between the brake member we, the coupling sleeve 2%! and the ball retainers 5354, the brake member and ball retainer have a limited axial relation to the coupling sleeve but the drive connection between the coupling sleeve and the ball retainer is not afiected thereby. However, the brake member I95 has a limited rotational movement relative to both the ball retainer and the coupling sleeve.

At theend of the forward stroke of the spindle, following disconnection of the collet 56 from the feed sleeve :62, the motor I4 is de-energized by automatic means not shown. When this occurs, the coupling spring II2 between the hub 96 and the annular member IE5, which has been partially wound by the axial and rotatable shiftable movement of the latter, will cause the member I06 to slightly overrun the sleeve 2% and thereby reposition the pins I2!l--I2;'i in the deepest parts of the notches I22--I22. At all times the pusher plate 56 is urged rearwardly by the spring 90 and as the rotation of the balls slows down the "pusher plate reacts through the balls and their retaining structure to urge the brake member IE6 rearwardly bringing the flange I88 into engagement with the frictional facing I It. The latter will act to quickly retard the rotation of the inertia members and allow the feed sleeve and associate parts to be influenced by the large spring '99 to return to their initial starting position.

The engagement of the flange N23 with the fricition material is not continuous during the braking operation but alternately in engagement and out of engagement until the rotating parts slow down appreciably. This results from the fact that as the rotation of the annular member IE5 is slowed, its speed of rotation will fall below that. ofthe coupling sleeve 20 causing the pins Mil-12!) to react as previously described and thrust the flange out of engagement with the friction material. This will occur several times during a braking operation. The in and outmovement of ,the braking element 105 imposes considerably less strain on the armature shaft of the motor than if the frictional material is continuously engaged once the braking operation is commenced.

Considering the operation of the mechanism as a whole, the starting of the motor I l will rotate the driving memberid and the coupling sleeve 26. The latter through the helical splines will drive the'shaft or spindle it and the tool carried thereby. Simultaneously with the rotation of the spindle, the couplingsleeve will also rotate the inertia members or -balls All through the connection formed by the pins 98 and Hill. The centrifugal action of the balls will-be converted by the pusher plate 55 into a linear motion advancing the feed sleeve tz. s The latter will abut the collet-66 andradvancethe spindle and the tool upo the work =-I nsta ntly after the-coupling sleeve 2%- commences to rotate, the pins J2lJ-l;2ll.- willsrideup the inclined sides of. their respective notchesv 522 and axially thrust the-annular memberllii and the ball cage structure slightly forward suflicient ;to; immediately-,-release the brake formed by the flange lllll and the stationaryfriction facing Ht.

Atapredeterminedpositign in the advance oftthe spindlewhich position canbe adjusted by rota? ,tion ofithemounting 35 relative to the fixed sleeve '18, the expandiblepertionsof the collet will be compressed thereby breaking the connection between the feed sleeve, and-. the spindle and releasing the spindle f or return movement under the influence of the spring Iii.

Longitudinal adjustment-of the sleeve 18 will also varythe position of the ring-shaped stop member 86 and theposition when the collar 84 abuts the same: -The member tit-functions as a forward :brake in the mechanism acting after the collar B l-abuts the-same to retard any rotation of the feed sleeve by virtue of its engagement with the collet. The-coiled springswall in the member cushion the shock of the engagement with the collar; i

, previouslymentioned the .coiled spring 42 serves to spring load the spindle. Normally the cross pin 26 fixed to thecoupling sleeve 20 is disposedin-spaced relationto the forward end of the driving member 3 as shown in Figs. l and 2.

J However,: as varying degreesbf. hardness are encountered by the'toolin,its advance through the work piecethe spring 42will yield allowing the couplingsleeve 2fl to drawback and reduce the axialthrust-of the spindle l0. As the hardness of the material encountered by the tool decreases the spring 42- -urges the coupling sleeve to its normalfor'ward position. Thus the'forward advance of the spindle and the tool carried thereby is automatically slowed or speeded up as the resistance to penetration encountered by the toolvaries; a

. The spring 42- is operable toyield with the same degree of resistance at any point in the advancement of the spindle. The spring acts through the helical splines coupling the sleeve 2i! to the spindle and regardless'of. the position of the spindlein its axial movement will spring load the spindle with ,the'sa'inedegree of pressurethrough- 'out-.its advance. In. operation, the maximum compression of the spring 42 is less than the space eh streassessmentlites. 'P Psi-i 5 release position so that when increased resistance is encountered by the tool causing the withdrawal of the coupling sleeve the brake is not engaged. Moreover, another important feature of this construction is the fact that the retraction of the coupling sleeve permitted by the spring 42 has no effect upon the operation of the inertia members. The weighted members or balls 48 continue to exert the same pressure to advance the spindle regardless of the compression of the spring 42and the rearward movement of the coupling sleeve,v Thus, although the spindle is spring loadedto vary its rate of advance, any variation in its'advance has no effect upon the means exerting pressure to urge it forwardly.

\ As also previously mentioned the character of the splined connection between the .coupling sleeve 20 and the drive member l8 and the spindle Hlperforms an important function in the operation of the mechanism. Not only do the splines coupling these members serve their nor:- mal function of drivinglyassociating these meme bers together but by reason of their helical formation they also control the advance of the spindle and. tool. Quite frequently in the operation of the mechanism burrs or chips are formed on the work piece, especially after the tool or drill has broken through a wall portion of the Work, which interengage with the helical cutting teeth on the drill and tend to urge the tool forward rapidly beyond it's'normal speed of advance. The helical splines on the coupling sleeve and the spindle in contradistinction to longitudinal splines function to hold the spindle back from too rapid ad- Vance if such interfering action occurs." The helical splines provide a cam action to resist the axial thrust of the driven shaft, thereby prevent ing the tendency for too rapid advance of the 'driven shaft beyond its normal speed of advance.

What we claim is: 7

1. A' tool feeding mechanism comprising, in combination, a rotatable and axially movable shaft operable to rotate andaxially move a tool holdingmeans adjacentto one end thereof, a pin; rality of. weighted members arranged circularly about the shaft and movable outwardly radially thereof, means operable to convert the centrifugal force resulting from the rotation of said weighted members about the axis of the shaft into a linear force for axially moving the shaft in the direction of said tool holding means, a driving. member disposed in alignment with the end of the shaft opposite to said tool holding means, a sleeve extending between said driving member and the adjacent end ofsaid shaft and enclosing the same therewithin, said sleeve providedinteriorly with helical splines of the same pitch and direction meshing with external helical splines both on the driving member and on the adjacent end of the shaft for operatively coupling the two together for joint rotation butproviding axial movement of the shaft relative to the drive member for preventing the tendency for too rapid advance of the driven member beyondits normal speed of advance, and means operatively coupling said weighted members with said sleevefor joint rotation therewith about. the axis of the shaft.

, 2. .A tool feeding .mechanism comprising, in combination, a driving shaft,a driven shaft disposed in axial alignment with the driving shaft andprovided at the end opposite to the driving shaft with means for rotating and axially moving a tool, means for coupling said shafts together for joint rotation and for preventing the tendency for qera d e vagqe 9f he r n sha t b yond gauges itsnormal speed of adv'ance,said meansincl uding a "cone-shaped pusher plate encircling the axisof rotation of the driven shaft and engageable therewith, a sleeve telescopically received over the adjacent ends of said shafts and provided 'interiorly with helical splines meshing with external helical splines on the two shafts for operatively coupling the same together but providing axial movement of the driven shaft relative to the driving shaft, an annular member encircling the axis of rotation of the driven shaft and provided with radially extending flanges forming outwardly opening pockets arranged circularly around the rotating axis of the driven shaft immediat'ely adjacent to said pusher plate, an inertia member in each of said pockets operable when rotated to move outwardly and exert a centrifugal force upon the pusher plate urging the same and the driven shaft axially in one direction, means coupling the annular member to the sleeve for joint rotation, and means for retarding rotation of the inertia members, said means including an element mounted on said annular member for joint rotation therewith and movable into and out of engagement with a fixed element, and means automatically operable to disengage said movable element from engagement with said fixed element when the annular member is rotatively driven by said sleeve and automatically operable to re-engage said movable element with said fixed element when the driving force imparted by the sleeve to the annular member is discontinued.

3. A tool feeding mechanism comprising, in

combination, a driven member supported for rotation and axial movement and provided adjacent one end thereof with means for rotating and axially moving a tool therewith, a driving member disposed adjacent to and in alignment with the end of the driven member opposite to said means, a metallic coupling sleeve enclosing the adjacent ends of said members and provided interiorly with helical splines engaging helical splines on the members for coupling the same together for joint rotation and preventing the tendency for too rapid advance of the driven member beyond its normal speed of advance, means responsive to the rotation of said driven member for axially advancing the same away from said driving member, means mounting said coupling sleeve for axial movement, and a coiled spring coaxial with said coupling sleeve and so mounted with respect thereto that it yieldingly urges the sleeve axially in the direction of the advancement of said driven member but is yieldable when increased resistance is encountered by the tool to allow the sleeve to retract axially toward the driving member.

4. A tool feeding mechanism comprising, in combination, a rotatable drive member, a rotatable driven member 'co-aXially aligned with said drive member and mounted for axial movement relative thereto, a metallic coupling sleeve member enclosing the adjacent ends of said drive and driven members and provided interiorly with helical splines engaging with helical splines on the drive and driven members for coupling the same for joint rotation but permitting axial movement of the driven member relative to the drive member and the sleeve member and preventing the tendency for too rapid advance of the driven member beyond its normal speed of advance, means responsive to the rotation of said sleeve member for axially advancing the drivenmemberin a direction away from 'said drive member; brake 'mea'nsfor retarding rota tionof said members including a fixed circular element and afrotatable circular element both being co-axiallyflrnountedwith respect to fsafd members and axially spaced apart from one an other, means coupling said rotatable brakeele ment to said sleeve member for joint rotatf' n therewith but providing a limited axial m" ve ment relativeth'ereto from a positioni in which said elements are engaged to a position which said elements are spaced apart, means mounting said sleeve member for axial movement relative to the other two members, spring means yieldingly urging the sleeve member in the direction of advancement of the driven member but yieldable when increased resistance is encountered by the driven member in its axial advancement to allow the sleeve to retract toward the driving member, said yielding means normally limiting the retracting movement of the sleeve member to less than the distance separating the brake elements in their spaced apart relationship.

5. A tool feeding mechanism comprising, in combination, a power operated rotatable drive member, a rotatable driven member co-axially aligned with said drive member and mounted for axial movement relative to the drive member, a metallic coupling sleeve telescopingly enclosing the adjacent ends of said members and provided interiorly with helical splines engaging with helical splines on the members for coupling the same together for joint rotation but permitting axial movement of the driven member and preventing the tendency for too rapid advance of said driven member beyond its normal speed of advance, a ball cage structure coaxially mounted with respect to said members and containing a plurality of weighted balls arranged about the axis of rotation of the members, means operable to convert the centrifugal force resulting from the rotation of balls by said cage structure "into a linear force for axially moving said driven member in a direction away from said driving member, means o'peratively coupling said sleeve 1 with said cage structure for joint rotation but providing a limited axial movement of one with respect to the other, a brake device including a fixed circular element and a rotatable circular element of corresponding radial dimensions arranged co-axially with respect to said members and axially spaced apart from one anothen'nieans operatively coupling said rotatable brake element to said cage structure 'for joint rotation and axial movement therewith but providing a limited rotational movement of the brake element with respect to the cage structure and said coupling sleeve. said rotatable brake element adapted 'to engage said fixed brake element in one position of its axial movement to retard rotation of said balls and to be spaced axially apart from said fixed brake element in. another position of its axial movement to release the brake from opeia tion, and means operable between said'coupling sleeve and said rotatable brake element and responsive to relative rotative movement thereof to axially shift the brake element to brake release position when the sleeve is power driven by said driving member.

6. In a tool feeding mechanism, a power oper ated shaft, a rotating and longitudinal spindle co-axially aligned with said shaft and provided on its forward end opposite to the shaft with means for rotating and longitudinally moving a cutting tool therewith, means operatively cone plin'g the adjacent end'ofsa'id 'sp'indleto'theshait but providing longitudinal movement of the spindle, spring means yieldingly opposing the-forward longitudinal movement of thezjspindle, a feed sleeve co-axial with said spindle and enclosing a portion of the length of the same, means responsive to the rotation of said shaft for longitudinally moving the feed sleeve in a forward direction, spring means yieldingly opposing the forward longitudinal movement. of thefeed sleeve, means coupling the feed sleeve to the spindle for joint forward movement comprising a collet encircling the spindle forwardly ofqthe feed sleeve and having the forward section thereof fixed to the spindle, the rear section of'said collet being split longitudinally to form a plurality of inherently resilient expandible arcuate segments adapted to abut the inner peripheralwsurfacexof the forward end of the feed sleeve, said segments each provided with a corresponding circularly aligned shoulder projecting outwardly into the path of travel 'of the-feedsleeve and "adapted to be engaged by the fogrwand end thereof for coupling the spindle to the feed sleeve for joint forward movement, said shoulders each provided with an inclined forward face, and an annular member co-axial with the spindle and so located with respect to the path of travel of the collet that at one point in the forward advance of the spindle it will engage the inclined forward faces of said shoulders and-simultaneously wedge the arcuate segments of the collet radially inwardly and retract the shoulders out of engagement with the feed sleeve.

"'7; A tool feeding mechanism comprising, in combination, a driving shaft',' a driven 'sha'ft on whicha tool is carried, a cone- 'shaped pusher plate engageable with the driven shaft, a sleeve extending between driving and driven shafts and helioally splined thereto for operatively couplirig the two shafts together for joint rotation but permitting axial movement of the driven shaft relative to the driving shaft and preventing the tendency for too rapid advance of the driven shaft beyond its normal speed of advance, a disc provided with radial raceways therein, inertia members confined between said pusher plate and said disc in said raceways and adapted to be rotated by the disc to exert a centrifugal force urging said pusher plate axially and thereby axially move the driven shaft, means coupling said disc to said sleeve for joint rotation therewith but providing limited axial movement of the disc relative thereto, and means for retarding rotation of the inertia members adapted to become effective upon axial movement of the disc in one direction relative to the sleeve.

8. Tool feeding mechanism comprising, in combination, a driving shaft, a driven shaft disposed in axial alignment with the driving shaft and provided with means for carrying a tool on the end thereof opposite to the driving shaft, a sleeve telescopically received over the adjacent ends of the shafts and provided interiorly with helically splined means for coupling the two shafts together for joint rotation but permitting axial movement of the driven shaft relative to the driving shaft and preventing the tendency for too rapid advance of the driven shaft beyond its normal speed of advance, a cone-shaped pusher plate encircling the axis of rotation of the driven shaft and engageable therewith for axially advancing the same in one direction, an inertia member retaining structure encircling the axis of rotation of the driven shaft and carrying a plurality of weighted inertia members adapted when rotated by the structure to move outwardlyi'al diall-y ofthe structure and exert a centrifugal force upon the pusher plate urging the same and the driven shaft axially in said direction, means coupling said structure to said sleeve for joint rotation therewith, means for retarding rotation of said inertia members including a non-rotatable "friction element carried by a stationary part of the mechanism and a friction element rotatable with said structure, means mounting one of said elements for movement into and out of engagementwith the other element, means urging said movable element into engagement with the other element to retard rotation of said inertia members, and means automatically operable-when said-sleeve is power driven by said driving shaft to disengage said elements from one another.

9. In a tool feeding mechanism, a rotatable drive shaft, a rotatable tool carrying driven shaft axially aligned with thedrive shaft and mounted foraxial tool feeding movement away from the drive shaft, a coupling sleeve telescoping the adjacent ends of the drive and driven shafts and helicall'y' splined "thereto for permitting axial movementof the driven shaft relative to the drive shaft and'preventing thetendency'for too rapid advance of the driven shaft beyond its normal speed 'of advance, "bearing support means for mounting the sleeve for axial movement relative to the drive shaft; and spring means urging the sleeve axially in the tool feeding direction of'the driven'shaft and'yieldingly resisting return movement thereof,

10. Ina tool feeding mechanism, a rotatable drive "shaft, a' rotatable- "driven shaft axially aligned withthe drive shaftand adapted to carry a tool, centrifugal force applying means for axially feeding the driven shaft away from the drive shaft, a sleeve telescoping the'ends of said. drive and said driven shafts and coupled to said force applying means for rotating the same, said sleeve provided interiorly with helical splinesengaging corresponding helical splines on the drive and driven shafts for coupling the same to-- gether for joint rotation but providing axial tool feeding movement of the driven shaft relative to the drive shaft and preventing the tendency for too rapid advance of the driven shaft beyond its normal speed of advance, bearing support means for mounting the sleeve for axial movement relative to the drive shaft, and a coiled spring co-axial with said shafts and mounted to yieldingly urge the sleeve in the direction of the axial feed of the driven member.

11. In a tool feeding mechanism, a rotatable drive shaft, a rotatable tool carrying driven shaft axially aligned with the drive shaft and mounted for tool feeding movement axially away from the drive shaft, a coupling sleeve telescoping the adjacent ends of the drive and driven shafts and helically splined thereto for coupling the two shafts for joint rotation but permitting said axial tool feeding movement of the driven shaft relative to the drive shaft and preventing the tendency for too rapid advance of the driven shaft beyond its normal speed of advance, a bearing encircling the sleeve and j ournaling the same for rotation, means providing axial movement of the bearing and coupling the sleeve and bearing for joint axial movement toward the drive shaft, and a coiled spring co-axial with said sleeve and mounted to engage said bearing and yieldingly resist movement thereof and the sleeve toward the drive shaft.

"12. In a tool feeding mechanism, a rotatable drive shaft, a rotatable tool carrying driven shaft axially aligned withsaid drive shaft and mounted for tool feeding movement forwardly of the drive shaft, a rotatable structure encircling the driven shaft, centrifugal force applying means forming a part of said structure and adapted upon rotation thereof to axially move the driven. shaft forwardly'of the drive shaft, a sleeve forming a part of the structure extending rearwardly thereof and helically splined to the adjacent ends of said shafts to couple the two shafts together for joint rotation while permitting forward tool feeding movement of the driven shaft and preventing the tendency for too rapid advance of the driven shaft beyond its normal speed of advance, a braking element forming a part of the structure movable into and out of engagement with a stationary frictional surface of the mechanism and adapted when engaged therewith to retard rotation of the centrifugal force applying means, and means responsive to driving impulses received by said sleeve from said drive shaft for automatically disengaging said element from said friction surface-and -further responsive to the discontinuance of said driving impulses to move said element into engagement with said friction surface.

13. In .a tool feeding mechanism, a rotatable drive shaft, a rotatable .tool carrying'driven shaft axially aligned with said drive shaft and mounted for tool feeding movement forwardly thereof, and centrifugal weight retaining sleeve means coaxial with'said shafts adapted upon rotation to move the driven shaft forwardly in tool feeding direction, said sleeve means telescopingly overlapping the adjacent ends of said shafts and being splined thereto with helical splines to couple the driven shaft and the centrifugal weight to the drive shaft for joint rotation therewith and prevent the tendency for too rapid advance of the 16 driven shaftbeyond its normal speed of advance -14. In a toolfeeding mechanism, a rotatable drive shaft, a rotatable tool carrying driven shaft axially aligned with said drive shaft and mounted for tool feeding movement forwardly thereof, centrifugal weight retaining sleeve means co-axial with said shafts adapted upon rotation to move the driven 'shaft forwardly of the drive shaft in tool feeding direction, said sleeve means telescopingly overlapping the adjacent ends of said shafts and-being helic'ally sp'linecl thereto to couple the driven shaft and the centrifugal weight to the drive shaft for "joint rotation therewith but permitting axial movement of the driven shaft relative to the drive shaft and preventing the tendency for too rapid advance of the driven shaft beyond its normal speed of advance, bearing support means for mounting said sleeve means for limited axial movement relative to the drive shaft, and means spring loading said sleeve means in said tool feeding direction and yieldably resisting movement of the sleeve means toward the drive shaft.

PHILIP S. CLAUS. 'EBER J. READMAN.

REFERENCES CITED The following references are of record in the f le of this patent:

UNITED STATES PATENTS Number Name Date 632,944 Jansen Sept. 12, 1899 1,277,300 Duncan Aug. 27, 1918 1,457,745 Norris June 5, 1923 2,207,340 Claus July 9, 1940 2,346,359 Claus Apr. 11, 1944 2,360,907 Stoner Oct. 24, 1944 2,410,091 Lynch Oct. 29, 1946 Certificate of Correction Patent No. 2,510,330 June 6, 1950 PHILIP S. OLAUS ET AL. ,7

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 10, line 57, after the Word splines strike out of the same pitch and direction and insert the same after splines in line 58;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 7th day of November, A. D. 1950 THOMAS F. MURPHY,

Assistant Oommz'ssioner of Patents. 

